Every person concerned in any act or omission in violation of this chapter, whether he directly performs or omits to perform any act in violation of this chapter, or aids or abets the same, whether present or absent, and every person who directly or indirectly counsels, encourages, hires, commands, induces, or otherwise procures another to commit such violation is, and shall be, a principal under the terms of this chapter, and shall be proceeded against and prosecuted as such.